On Jan 20, 2008 12:44 PM, Stefano Simonetti [email protected] wrote:
Hi to all, I would like to test my "old" AO40 13cm converter (2400-2402MHz) to see if it is still alive...
I have not any kind of RF generator and I am wondering if some satellite has now active some tx in that band.
Thanks, 73
IW1RDZ - Steve
Steve:
I don't believe there is a permanent S-band signal in LEO that makes an easy means of testing your downconverter. The CanX-2 cubesat will have a downlink in s-band, but some modulation modes are less useful for setting up a system than others, and I can't tell what modulation they'll be using, or on what frequency, exactly.
I guess we might have S-band from the ISS some time soon, too.
If you need a cheap-and-dirty signal source, try using one of those small, canned RF oscillators at 40 MHz. Properly powered with a 5v voltage regulator and a 9v battery, it will produce a harmonic signal that you'll hear well from right next to the downconverter, and, with a gain antenna, from some distance away. Don't worry about building it an antenna. If you're not sure if what you're hearing is the sig gen. or a birdie, just blow on the sig gen, and its frequency will warp!
At $2, it was all I used to hack and tweak my downconverter. I got this idea from a VE2 ham's webpages, but I can't seem to google them up right now.